package com.codes.utils.IPUtils;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UdpGetClientMacAddr {
    private String sRemoteAddr;
    private int iRemotePort = 137;
    private byte[] buffer = new byte[1024];
    private DatagramSocket ds = null;

    public static void main(String[] args) {
        try {
            //要获取的机器mac地址的ip
            UdpGetClientMacAddr mac = new UdpGetClientMacAddr("192.168.2.114");
            String ma = mac.GetRemoteMacAddr();
            System.out.println(ma);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public UdpGetClientMacAddr(String strAddr) throws Exception {
        sRemoteAddr = strAddr;
        ds = new DatagramSocket();
    }

    protected final DatagramPacket send(final byte[] bytes) throws IOException {
        DatagramPacket dp = new DatagramPacket(bytes, bytes.length, InetAddress
                .getByName(sRemoteAddr), iRemotePort);
        ds.send(dp);
        return dp;
    }

    protected final DatagramPacket receive() throws Exception {
        DatagramPacket dp = new DatagramPacket(buffer, buffer.length);
        ds.receive(dp);
        return dp;
    }

    protected byte[] GetQueryCmd() throws Exception {
        byte[] t_ns = new byte[50];
        t_ns[0] = 0x00;
        t_ns[1] = 0x00;
        t_ns[2] = 0x00;
        t_ns[3] = 0x10;
        t_ns[4] = 0x00;
        t_ns[5] = 0x01;
        t_ns[6] = 0x00;
        t_ns[7] = 0x00;
        t_ns[8] = 0x00;
        t_ns[9] = 0x00;
        t_ns[10] = 0x00;
        t_ns[11] = 0x00;
        t_ns[12] = 0x20;
        t_ns[13] = 0x43;
        t_ns[14] = 0x4B;

        for (int i = 15; i < 45; i++) {
            t_ns[i] = 0x41;
        }

        t_ns[45] = 0x00;
        t_ns[46] = 0x00;
        t_ns[47] = 0x21;
        t_ns[48] = 0x00;
        t_ns[49] = 0x01;
        return t_ns;
    }

    protected final String GetMacAddr(byte[] brevdata) throws Exception {

        int i = brevdata[56] * 18 + 56;
        String sAddr = "";
        StringBuffer sb = new StringBuffer(17);

        for (int j = 1; j < 7; j++) {
            sAddr = Integer.toHexString(0xFF & brevdata[i + j]);
            if (sAddr.length() < 2) {
                sb.append(0);
            }
            sb.append(sAddr.toUpperCase());
            if (j < 6)
                sb.append(':');
        }
        return sb.toString();
    }

    public final void close() {
        try {
            ds.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public final String GetRemoteMacAddr() throws Exception {
        byte[] bqcmd = GetQueryCmd();
        send(bqcmd);
        DatagramPacket dp = receive();
        String smac = GetMacAddr(dp.getData());
        close();

        return smac;
    }
}